In a third generation partnership project (3GPP) long term evolution (LTE) or LTE-advanced (LTE-A) system, downlink multiple access manners generally use an orthogonal frequency division multiple access (OFDMA) manner. In time, a length of a radio frame is 10 ms, including 10 subframes, each subframe is 1 ms, each subframe includes two time slots, and each time slot includes seven (when a normal cyclic prefix is used) or 6 OFDM symbols (when an extended cyclic prefix is used). In frequency axis, a radio frame consists of a plurality of subcarriers, and a subcarrier in an OFDM symbol is called a resource element (RE). Twelve subcarriers and a time slot form a resource block (RB).
Various data carried in a subframe is mapped by various physical channels divided in physical time frequency resources of the subframe. For instance, a physical downlink control channel (PDCCH for short), a cell common reference signal (CRS for short), and a physical downlink shared channel (PDSCH for short) and etc may be included. In existing LTE R10 and R11 systems, the subframe may be divided into two types approximately. One type is a normal subframe, for two situations regarding the extended cyclic prefix (CP for short) and the normal CP as described above, where the physical downlink control channel is provided in the first three or the first four symbols of the first time slot, common pilot is provided in the fourth or fifth symbol, and dedicated pilot is provided in the last two symbols, respectively. The other is a special subframe, for instance, which is configured in subframes 0 and 5 in the case of the normal CP is used, and in subframes 0, 4 and 7 in the case of the extended CP is used, where the dedicated pilot is not provided.
In a new LTE R11 version, a new carrier type (NCT for short) is provided, where the physical downlink control channel and the common pilot are not set any more. Instead, only the dedicated pilot, i.e. a user equipment (UE for short)-specified reference signal, is relied on for signal demodulation. The resource elements which was provided for the physical downlink control channel and the common pilot before in a physical resource block is used for transmitting downlink data or an enhanced physical downlink control channel. In a case of NCT, the transmitted special frame cannot be demodulated by a receiving device since there isn't a reference signal; while for a normal subframe, channel estimation quality at the receiving end will also be poor since the dedicated pilot is provided in the last two symbols of the first time slot. Thus, the existing dedicated pilot design is not adaptable to the new NCT scheme, which will affect communication data demodulation performance of a user equipment.